US military and intelligence officials said the releases are evidence that parts of Pakistan's security establishment continue to support the Afghan Taliban.
The officials refused to divulge many details of the freed Taliban commanders, but said that they were 'high-ranking Taliban members'.
"The capture of Baradar was positive, any way you slice it. But it doesn't mean they've cut ties at every level to each and every group," The Washington Post quoted a US counter terrorism official, as saying.
"They did, in fact, capture and release a couple," said another US military official adding that the ISI's purported decision to do so "speaks to how hard it is to change your DNA."
"The ISI wants to be able to resort to the hard-power option of supporting groups that can take Kabul, if the United States suddenly leaves," said a US military adviser briefed on the matter.
However, Pakistani officials have denied the claims, saying the ISI is committed to dismantling insurgent groups.
He rubbished reports regarding any Taliban operatives been released after being captured.